利用微生物制剂进行污泥减量的生产性试验研究

在重庆市江津区的德感污水处理厂开展了利用多功能复合微生物制剂（MCMP）进行污泥减量的生产性试验研究,结果表明：在氧化沟的好氧段投加MCMP,当投加频率为1次／月、每次的投加量为日处理水量的0.005％时,污泥减量效果明显,系统运行了6个月而没有外排剩余污泥。投加MCMP后不仅能保证污水处理厂的出水水质达到《城镇污水处理厂污染物排放标准》（GB18918-2002）的一级B标准,而且还强化了对氮、磷的去除。该技术不用增加或改变原有污水处理设施,也无需改变原有工艺的运行方式,具有显著的经济、环境和社会效益。     

仿生态复合酶制剂用于剩余污泥减量的试验研究

采用仿生态复合酶制剂在某污水处理厂进行剩余污泥减量试验。设A、B、C三组相同装置,A不投加酶制剂,而B、C组分别投加约为处理水量0.01%和0.02%的酶制剂,均采用常规活性污泥法且运行操作相同,比较三组试验装置的污泥减量效果。结果表明:相比于A组,B、C组的剩余污泥减量效果分别达到了38.4%、56.7%,并且对出水水质没有消极影响,反而提高了对TN、TP的去除效果。A、B、C组出水COD均值分别为37、42、46 mg/L,氨氮均值分别为1.76、1.36、1.52 mg/L,TN均值分别为17.9、13.5、14.3 mg/L,TP均值分别为0.54、0.45、0.37 mg/L。通过估算,投加0.01%~0.02%酶制剂进行污泥减量,其处置成本仍然高于传统的填埋,但污泥焚烧处置的推广,将为酶制剂污泥减量技术提供广阔的市场应用前景。     

利用同步臭氧氧化实现SBR污泥减量的研究

将臭氧通入SBR反应器中进行同步臭氧氧化,考察了污泥的减量效果以及对出水水质的影响.结果表明:污泥产率随着臭氧投量的增加而减小,当臭氧投加量从零增加到O.04gO3/gSS时污泥产率从0.45 gSS/gSCOD减少到-0.04 gSS/gSCOD;同步臭氧氧化对SBR系统的出水水质没有显著影响,当臭氧投加量为0.03 gO3/gSS时系统对COD、NH4 -N、TP的去除率分别为92.5%、91.1%、80.5%.可见,同步臭氧氧化是实现污泥减量的有效方法.     

水解酸化池预处理低碳生活污水的效能分析

为了提高低碳氮比生活污水的脱氮效能,在缺氧池前设置水解酸化池,通过水解酸化作用改善进水碳源,同时对回流剩余污泥进行降解,以期达到改善进水碳源可生化性、提高其可利用率、减少外碳源投加量并实现污泥减量的目的。分别考察了水解酸化池对污水单独进行预处理以及对污水和回流污泥同时进行预处理情况下的作用效能及其对系统脱氮的影响。结果表明:两种预处理条件下,理论B/C值都大于0.65,出水SCOD/COD的平均值和出水VFA浓度均高于进水,单独污水水解酸化的出水SCOD减少较多,对TN的去除率仅为47.8%;回流剩余污泥后,温度>20℃且每日分4次共回流20 L剩余污泥的TN去除效果明显优于单独污水水解酸化和温度<20℃且每日分2次共回流10 L的运行效果,两种回流量条件下对TN的去除率分别为71.9%和66.1%,污泥减量率分别为58%和56.3%。     

超声波溶胞作用对脱氮除磷系统的影响

探讨了超声波作用后的剩余污泥回流至A2/O系统对污泥减量和处理效果的影响,为污水处理开辟新的碳源,对实现污泥减量及资源化进行了有益的尝试。试验结果表明:超声波作用10 min后的剩余污泥回流至A2/O系统中,系统表观产率降低;剩余污泥回流至厌氧池、缺氧池、好氧池,其减量效率分别为35.99%、31.04%、30.14%。同时,出水COD、TN、NH3-N、NO3-N与未回流剩余污泥(超声作用后)时相比较高,但均达到了GB 18918—2002《城镇污水处理厂污染物排放标准》一级B出水标准。出水TP会超过1 mg/L,这主要是由出水浊度较高引起的。     

多功能微生物制剂用于污泥减量的研究

目前如何减少剩余污泥的产量已成为污水处理的研究热点。为此，基于目前主要的污泥减量理论，在自然界中分离、筛选出一些特殊的微生物菌种，在特定培养工艺下研制一种多功能微生物制剂（MCMP）用于污泥的减量。采用该微生物制剂在重庆长寿污水处理厂进行中试：设3套相同装置，均采用常规活性污泥法且运行操作相同，其中两套装置分别投加所处理水量0．005％和0．01％的微生物制剂，一套不投加，对比其污泥减量效果。试验结果表明：投加MCMP的两套装置的污泥减量比例分别为81．76％和89．18％，3套装置的污泥增长速率分别为2．0％、1．5％和11．5％；投加MCMP能提高出水水质，3套装置出水的COD、NH3-N平均浓度分别为35．08、33．89、36．51mg／L和1．40、1．22、1．62mg／L。投加MCMP不用增设专用的处理单元，也不需改变原有的处理设施及运行方式。3套装置的曝气量相同，因而投加MCMP不会增加整个系统的动力消耗。该制剂具有良好的污泥减量效果，能减轻污水处理厂污泥处理、处置的负担。     

水厂药剂投加优化与应用

通过分析各净水药剂间关联性,确定了聚合氯化铝(PAC液体)、臭氧、聚丙烯酰胺(PAM)的最佳投加量,在保证出水水质的前提下,有效控制了药剂成本。生产运行表明,预臭氧最佳投加量为0. 5～0. 7 mg/L,可显著提高絮凝效果,使PAC投加量降低20. 7%;在控制PAC用量的基础上,合理控制平衡池污泥浓度(最佳3%),可减少58. 9%的PAM投加量。降低2种药剂的使用量并控制泥饼含水率后,污泥运输量减少了54%,大大降低水厂的运行成本。     

脱氮型污泥减量技术研究

为减少缺氧—好氧活性污泥法脱氮工艺中剩余污泥的产生量,采用流化填料组成缺氧—好氧—全氧化系统,对其脱氮型污泥减量效果进行了试验研究。结果表明:缺氧—好氧—全氧化系统的平均污泥减量率为65%、对总氮的平均去除率为62%,此外系统对TOC也有较好的去除效果。显微镜观察发现,投加填料后缺氧池和好氧池中形成了"细菌—原生动物—后生动物"的较长食物链,有利于污泥减量,可见该工艺同时具有良好的脱氮和污泥减量效果。     

污泥浓缩池中磷的释放及其强化去除措施

城市污水处理厂污泥浓缩池上清液和脱水机滤液重新回流入污水处理系统会增加系统的磷负荷。针对污水处理厂剩余污泥浓缩过程中浓缩时间、投加聚合氯化铝(PAC)以及曝气对磷释放的影响进行了研究。结果表明,污泥浓缩池中的剩余污泥静置4 h后,释磷速率显著加快。在污泥浓缩池投加0.1 g/g干泥的PAC不仅将快速释磷时间延迟至8 h,还可以显著降低上清液中的磷酸盐浓度。对污泥浓缩池曝气30 min且溶解氧达到3 mg/L以上时,上清液中磷酸盐浓度降低了77.7%。通过合理控制剩余污泥在浓缩池中的停留时间、投加PAC以及曝气等,可以降低浓缩池上清液磷浓度,有效提高系统的除磷效果。     

二沉池强化沉淀对污水处理系统稳定性的影响

针对二沉池出水悬浮物(SS)较高,下一级过滤工艺高负荷运行,出水SS触及指标预警值高频出现的问题,在二沉池投加聚丙烯酰胺(PAM)进行强化沉淀,提升了二沉池的处理效率和出水水质稳定性。PAM不同投加量对聚合氯化铝(PAC)投加量、二沉池运行情况影响的分析表明,在一定范围内,用于强化沉淀的PAM投加量越大,出水SS、TP越稳定,且PAC投加量较低,总体药耗降低,化学产泥量减少对整体产泥率降低贡献较大。     

Effect of low ORP in anoxic sludge zone on excess sludge production in oxic-settling-anoxic activated sludge process

This paper studied the effect of oxidation-reduction potential (ORP) in the anoxic sludge zone on the excess sludge production in the oxic-settling-anoxic process (OSA process), a modified activated sludge process. Two pilot-scale activated sludge systems were employed in this study: (1) an OSA process that was modified from a conventional activated sludge process by inserting a sludge holding tank or namely the "anoxic" tank in the sludge return line; and (2) a conventional process used as the reference system. Each was composed of a membrane bioreactor to serve the aeration tank and solid/liquid separator. Both systems were operated with synthetic wastewater for 9 months. During the operation, the OSA system was operated with different ORP levels (+100 to -250 mV) in its anoxic tank. It has been confirmed that the OSA system produced much less excess sludge than the reference system. A lower ORP level than +100 mV in the anoxic tank is in favor of the excess sludge reduction. When the ORP level decreased from +100 to -250 mV the sludge reduction efficiency was increased from 23% to 58%. It has also been found that the OSA system performed better than the reference system with respect to the chemical oxygen demand removal efficiency and sludge settleability. The OSA process may present a potential low-cost solution to the excess sludge problem in an activated sludge process because addition of a sludge holding tank is only needed.     

Possible cause of excess sludge reduction in an oxic-settling-anaerobic activated sludge process (OSA process)

Modification of a conventional activated sludge process by inserting a sludge holding tank in a sludge return line forms an oxic-settling-anaerobic (OSA) process that may provide a cost-effective way to reduce excess sludge production in activated sludge processes. In this paper we systematically evaluate the following possible scenarios that may explain the reduction of excess sludge in the OSA process: (i). energy uncoupling, (ii). domination of slow growers, (iii). soluble microbial products (SMPs) effect and (iv). sludge decay in the sludge holding tank under a low oxidation-reduction potential (ORP) condition. Results show that only the final scenario may reasonably explain this reduction. It has also been found that the sludge decay process in the sludge holding tank may involve the reduction of the cell mass.     

Feasibility of using a chlorination step to reduce excess sludge in activated sludge process

The ultimate disposal of excess sludge generated from activated sludge processes has been one of the most challenging problems for wastewater treatment utilities. Previous work has shown that excess sludge can be minimized successfully by using sludge ozonation to dissolve it into substrates to be oxidized in the aeration tank. However, this approach is a costly option. Therefore, as an alternative solution, we propose to use chlorination to replace ozonation in excess sludge minimization in the light of operational cost. To investigate the feasibility of this low cost approach, this paper mainly focuses on the effect of chlorination on sludge reduction rate, formation of trihalomethanes, sludge settleability, and effluent quality. Two identical activated sludge membrane bioreactors were continuously operated with synthetic wastewater under the same operation conditions for several months. During this period, one pilot unit was used as the reference system without chlorination of excess sludge, while another served as a testing unit, where excess sludge was taken out for conducting chlorination at a dose of 133mg/g MLSS every day and the chlorinated liquor was then returned to the aeration tank. The sludge production rate and the water quality of both the units were analyzed daily. It was observed that the sludge production could readily be reduced by 65% once the chlorination treatment was involved. However, the chlorination treatment also resulted in poor sludge settleability as well as significant increase of soluble chemical oxygen demand in the effluent, which creates potential difficulties in the operation of a conventional treatment plant with gravity clarifiers. However, it has been demonstrated that by integrating the immersed membrane into the activated sludge process these difficulties can be overcome effectively.     

HA-A/A-MCO工艺水解酸化单元运行性能研究

针对现有污泥减量技术中存在的氮、磷去除率低的问题,开发了一个新型的具有同步除磷脱氮和污泥减量功能的HA-A/A-MCO工艺,对回流污泥种类及比例对水解酸化池产酸、污泥减量及系统释磷效果进行研究,结果发现：回流污泥种类及比例影响水解酸化出水VFA总量进而影响释磷效果,回流2%厌氧释磷污泥水解产生的VFA总量最大（275 mg/L）,系统释磷量也最大（57 mg/L）。     

旁路微氧污泥减量效果及其影响因素

通过对旁路微氧污泥减量技术中好氧污泥在微氧池中的减量效果及其影响因素的研究,发现污泥减量效果与微氧池的污泥浓度(MLSS)、好氧污泥与厌氧污泥的比例(α)、微氧池的氧化还原电位(ORP)、微氧池的污泥停留时间有关。当微氧池的α=2∶8、MLSS为10 000 mg/L时,减量效果最佳;通过不同MLSS和不同α值两组试验,得出在最佳值时的减量率分别为19.15%和19.61%。低ORP值条件下微氧池污泥颗粒细碎,中位粒径为20.24μm,而好氧污泥的中位粒径为32.18μm。同时,混合液中溶解性大分子有机物含量明显增加。该工艺使污泥有更充分的时间进行内源呼吸和EPS的离解释放,从而实现了污泥减量。     

驯化耐盐活性污泥处理高盐度工业废水

以某石化企业废水处理厂纯氧曝气池剩余污泥为接种污泥,采用逐步提高盐度负荷的方法对活性污泥进行耐盐性驯化,考察了驯化效果.结果表明,经过较长时间的驯化,活性污泥微生物能够适应高盐度的生存环境并能在其中生长、繁殖.驯化后的活性污泥能较好地抵御高盐度冲击负荷.在进水TDS为18～35 g/L的条件下,驯化后的活性污泥纯氧曝气池对高盐度工业废水中COD的平均去除率为85.7%,比原废水处理厂常规活性污泥纯氧曝气池的高出近10%.该驯化方法可以驯化出能耐受较高盐浓度并具有良好COD降解性能的耐盐活性污泥.     

剩余污泥回流至初沉池对A/O污水处理系统的影响

基于静态模拟试验结果，进行了将A／O处理工艺中二沉池剩余污泥按比例回流至初沉池的生产性试验，运行结果显示，这一措施能明显提高初沉池的沉淀效率，且当剩余污泥的回流比例为40％～60％时，初沉池对SS、COD等去除效果最佳，同时可提高A／O池进水的可生化性及处理能力，并降低浓缩池出泥含水率。该工艺运行稳定，可有效降低污水处理厂的总体运行成本。     

污泥减量工艺:HA-A/A-MCO的好氧脱氮机制分析

针对污泥减量技术存在对氮、磷去除能力低的问题,开发了一种具有强化脱氮除磷功能并可实现污泥减量化的HA-A/A-MCO工艺。在该工艺取得同步脱氮除磷和污泥减量优异效果的条件下,采用其处理校园生活污水,当进水TN平均为47 mg/L时,出水TN为10.9 mg/L,系统的总脱氮率为76.8%,其中好氧脱氮量占总脱氮量的50%,缺氧脱氮量占26%;HA-A/A-MCO系统存在着在好氧条件下具有反硝化能力的菌属,对好氧脱氮有一定贡献,且DO浓度对其反硝化能力没有抑制作用;好氧池中的DO浓度梯度有利于在污泥絮体内形成缺氧环境,从而促进同步硝化反硝化(SND)的发生,但减小污泥絮体尺寸会削弱絮体内部缺氧区域比例、降低SND的脱氮效率。